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E. LEES AND H. W. RIDSDALE.

NET CUTTER 0F AUTOMOBILE TORPEDQESQ APPLICATION man MAY 29. me.

1 309,252. v Patented July 8, 1919.

THB WLUMBIA PLANOGRAPH cm, WASHINGTON, D- C.

its

To all iii may concern: I

#Be it known that we, EnGAR Lnns and HnRBnnT -W1IEATLEY;RID'SDALE, both subjects ofathe King of Great Britain, residing at Portland 'Harbour Torpedo Works, Weymouth, inthe county of Dorset, England,

have invented certain new and useful Im- ,provementsin' or Relating to the N et-Cutters of Automobile Torpedoes, of which the following is a specification.

. The present invention relates to the net cutters of automobile torpedoes. These cutters 'ashitherto designed have been generally more or less defective owing to the factth'at,

though the kind of net that may be encountered under war conditions cannot be predicted with certainty, the cutters have either been suitable for dealing with only a limited range of diameter or size of mesh, or for any diameter of mesh in which case as in the lance-head type of cutter) the cutting 1s done on so many edges at once (generally 'four) that the eilectiveness is greatly re- 7 I "duced. It must be assumed that the net to be encountered may have a mesh of any diameter, the maximum being nearly that of the torpedo itself. Evidently those cutterswhich have only one cutting position, near 7 A the axis of the torpedo, will be ineffective in the case of the torpedo entering a large mesh nearly co-axially, while those cutters (such as the lance-head type) .having about four I cutting edges extending from a point near the axis for a distance approximately equal to half the diameter of the torpedo, will, on encountering any sized mesh, be liable to cut on all their sides at once, thus reducing t the cutting efliciency; the momentum of the torpedo may thereby be so much reduced that not enough remains to eflect any fur- 'ther cutting, though in the case of a net having a small mesh the cutting of several I j meshes may be necessary to enable the torpedo'to pass through the net. Again a torpedo provided with cutters arranged at or near the part of greatest diameter may be arrested if two or more of them come into operation simultaneously on the very thick strand which is characteristic of a large mesh net, or in the case of the torpedo encountering a small mesh net, the cutting done near one side of the maximum di ameter Specificationof Letters Patent.

E TATES PATENT 'onnron. 7 GAF rinnfsiinnnnnnnnr, WHEATLEY: nInsnAnE, wnxiuou'rrr, 1 GN T9 TEE WHITEHEAD TORPEDQWORKS (WEYMOUTH) LIMITEnor QWEYJuOUTH ENGLAND. E

j? NET-CUTTER or AUToMoBILE 'ronrn nons,

'.Patented Ju1y 8, 191 9.

'- Application filed May 29,1918. Seria1No.237,341.

may leave sufficient meshes intact elsewhere toarrest the torpedo Moreover some of the existing cutters are so designed that parts of two meshes are liable to enter the jaws of the cutter at one time, in which case the torpedo is arrested unless both parts can be cut by theone cutter.

According to our invention we provide a cutter of the lance-head type having two or more bladeswhich are so constructed and arranged that a net having a mesh of any diameter .can be cut in only one place at a time, so that whatever may be the diameter of mesh there will always be a cutter appropriate for dealing with it. The ordinary striker for firing the explosive charge may be prolonged and the prolongation made of suflicient length to enable the usual whiskers to be dispensed with without seriously increasing the angle of inefl'ective impact of the torpedo. The cutter surrounds this prolonged striker, and consists essentially of two, three or more radial blades. As a small angle of ineffective impact is much more important in the horizontal than in the vertical. plane, the profile of those blades which lie in or near the horizontal plane should not project beyond a straight line which is a tangent to the horizontal profile of the torpedo and passes through the end of the striker prolongation. Those blades which lie in or near the vertical plane may on the other hand exceed the limits of a" straight line which is a tangent to the vertical profile of the torpedo and passes through the end of the striker prolongation.

One only of the blades may be provided with a cutting edge which may be beveled, serrated or sharpened, the remaining blades being left relatively blunt, and in this case all the blades have straight or smoothly curved'profiles. It will be seen that such a cutter can only cut one mesh at a time and at only one point on the circumference of the mesh, while being suitable for dealing with any diameter of mesh.

In order that the said invention may be clearly understood and readily carried into 15 1 twnXEjt. 1 1 c What Weclaim fand desire to: secure: by

-- blades =which WiH'CHt-"EL netha ving' ar-mesh ter, and" h V Y I Fi'gf'Q'iS a section taken approximately on the line 4, '4; Fig. 3 and viewed from shown. Each blade is' of straight or smoothly curved profi1e,,only. one of these c blades (the Vertical @116. AJifithe example shown) being formed with a cutting edge, the others bcihg mei'ely" rounded; The said vertical blade may, ,as ]indicatedWbyi-chain lines 'in Fig. 1, project beyond a line which vt iopigiesno i this patent may be ob tainedatord five cents each bj addmssingthei cpmmfssionen otwPafentg;

through; 13118:,61161' of the striker; prolong-av- Letters Patent of the United- States isxz'' 11. In? an automobile torpedo; a net cutter of the lance-head typehaming zt'plumahty' of of any diameter inonlyfone-plac-a at-a: time.

2. 1111 an automobile torpedo, afnet cutter oi the-laflce-headtype; halving'w-plumlity of blades only one (if whichis rm ig t Cutting. edge In an automobile tor pedo a, net cutte r .c of the 1ance head type having. threeblades one 'of which i's'wfrtic zt'l andi' fofnie'd with a cutting edge and the others' fii'eihnpmvided With cutting'e'dgednd arranged zit" an angle of substantia lly onehundred and twenty de- I gi'ees fi'om each other and from the vertical blade; I l

'Tnit'nautomobile tofpedmthebqifibifia-f tionwithgwnetrrcutter of the lance-head 7 type having aplurality of blades which will gentiah to the" torpedoand passes; thi'bugh theouteFendrof said striker. t

Washington, 1 my 

